immune system-biochem Flashcards
innate immune system
derive from myeloid precursors whereas cells associated with the adaptive immune system are derived from common lymphoid precursor
one exception ….
natural killer cells are lymphocytes but NOT adaptive
examples of granulocytes
mast cells, eosinophils, basophils, neutrophils
mast cell
release mediators that trigger permeability,vasodilation,chemotaxis e.g. histamine allergic response
eosinophils
attacks parasites allergic reaction
basophils
involved in parasite defence
neutrophils
army foot soldier,phagocutes,signal to other parts of the immunes system
examples of antigen presenting cells
macrophages,dendritic cells,B-cells
macrophages
phagocytose-remove dead cells and debris -communicate with other immune cells,initaite adaptive immune system
dendritic cells
phagocytose
communicate with other immune cells
bridge between innate and adaptive immunity
initiate immune response
b-cells
present antigen to Tcells->cytokines
clonal expansion
antibodies
which immune cells are both phagocytic and antigen presenting cells
DENDRITIC cells
cytokines-activating T cell mediated response
il-12, IL-2,interfeorn-IFN-y,tumour necrosis factor-TNF-a
TH1=CD8=cytotoxic,T cells ,NK cells, macrophages,Bcells
cytokines activating antibody production-humeral response
IL-4,IL-5,IL-13
TH2=B cells,granulocytes
(eosinophils, parasite, extracellular)
complement cascade
part of the innate immune system C5a-chemotaxis C3b-opsonisation C5a and C3a-mast cell activation C5b...C9->forms a hole called membrane attack complex:cell LYSIS
lectin pathway
mannose binding lectin is produced in the liver in response to inflammation or ficolin in plasma.The MBL binds to carbohydrate on the surface of the pathogen, triggering the cascade
classical pathway
an antibody binds to a pathogen, and the antibody-antigen complex triggers the cascade
alternative pathway
a complement protein binds to a carbohydrate on the surface of the pathogen, and this triggers the cascade
leukocytes are recruited to the site of tissue injury by what
chemotaxis:process of bringing immune cells where the pathogen is
thanks to chemokine and complement proteins C5a